#!/usr/bin/env python
"""
@file    route2alts.py
@author  Daniel.Krajzewicz@dlr.de
@date    11.09.2009
@version $Id: route2alts.py 8993 2010-08-26 07:20:13Z behrisch $

Counts possible routes for all depart/arrival edges.
Builds route alternatives assigning the so determined probabilities to use a route.

Please note that the cost of the route is not computed!

Copyright (C) 2008 DLR/TS, Germany
All rights reserved
"""
import sys, optparse, array
from xml.sax import make_parser, handler

class RouteCounter(handler.ContentHandler):
    def __init__(self):
        self._routeCounts = {}
        self._odCounts = {}
        self._odRoutes = {}

    def startElement(self, name, attrs):
        if attrs.has_key("edges"):
            route = attrs["edges"]
            edges = route.split(" ")
            od = ( edges[0], edges[-1] )
            # count od occurences
            if od in self._odCounts:
                self._odCounts[od] = self._odCounts[od] + 1 
            else:		
                self._odCounts[od] = 1
            # count route occurences
            if route in self._routeCounts:
                self._routeCounts[route] = self._routeCounts[route] + 1 
            else:		
                self._routeCounts[route] = 1
            # build map od->routes
            if od not in self._odRoutes:
                self._odRoutes[od] = []
            if route not in self._odRoutes[od]:
                self._odRoutes[od].append(route)

    def endDocument(self):
         self._odRouteProbs = {}
         for od in self._odCounts:
             self._odRouteProbs[od] = {}
             absNo = float(self._odCounts[od])
             for route in self._odRoutes[od]:
                 self._odRouteProbs[od][route] = float(self._routeCounts[route]) / absNo

class RoutePatcher(handler.ContentHandler):
    def __init__(self, stats, out):
        self._stats = stats
        self._out = out
        
    def startElement(self, name, attrs):
        if name!="route":
            self._out.write('<' + name)
            for a in attrs.keys():
                self._out.write(' ' + a + '="' + attrs[a] + '"')
            self._out.write('>')
        else:
            self._out.write('\n        <routeDistribution last="0">\n')
            route = attrs["edges"]
            edges = route.split(" ")
            od = ( edges[0], edges[-1] )
            self._out.write('            <route cost="1" probability="' + str(self._stats._odRouteProbs[od][route]) + '" edges="' + route + '"/>\n')
            for r in self._stats._odRouteProbs[od]:
                if r==route:
                    continue
                else:
                    self._out.write('            <route cost="1" probability="' + str(self._stats._odRouteProbs[od][r]) + '" edges="' + r  + '"/>\n')
            self._out.write('        </routeDistribution>\n    ')


    def endElement(self, name):
        if name!="route":
            self._out.write('</' + name + '>')

    def characters(self, content):
        self._out.write(content)


if len(sys.argv) < 3:
    print "Usage: route2alts.py <INPUT_FILE> <OUTPUT_FILE>"
    sys.exit()
# count occurences
print "Counting alternatives occurences..."
parser = make_parser()
counter = RouteCounter()
parser.setContentHandler(counter)
parser.parse(sys.argv[1])
# build alternatives
print "Building alternatives..."
out = open(sys.argv[2], "w")
parser = make_parser()
parser.setContentHandler(RoutePatcher(counter, out))
parser.parse(sys.argv[1])

